Estimating Evaporation from Lakes and Reservoirs under Limited Data Condition in a Semi-Arid Region

Abstract

The Bowen ration energy balance (BREB) is considered as a standard method for estimating lake evaporation. The BREB method however requires numerous input data which may not be readily available especially in developing countries. This limitation could be solved by using methods with fewer data requirements. Evaporation from lakes and reservoirs in Iran is commonly estimated using pan evaporation because there have not been a consensus on which methods are most applicable under the limited data condition and arid climate. Therefore, the objective of this research was to determine the most appropriate evaporation methods over Doosti dam reservoir in Iran. Eighteen existing methods were tested and ranked based on the BREB method. The Jensen-Haise, Makkink, Penman and deBruin methods were among the most consistent methods with BREB in which the RMSD values were obtained 1.2, 1.34, 1.62 and 1.65 mm d −1 , respectively. Finally, we concluded that methods which rely only on air temperature, or air temperature combined with sunshine data (e.g., Jensen-Haise and Makkink), were relatively cost-effective options for estimating evaporation at the study area due to their simplicity, least sensitivity and high accuracy.Nomenclature E the evaporation rate (mm d −1 ) R n the net radiation (W m −2 ) N the change in the energy storage in the water (W m −2 ) λ the latent heat of vaporization c the specific heat of water (J kg −1 ) F in and F out the heat fluxes from water flows in and out of the water body (W m −2 ) F P the heat inflow from precipitation (W m −2 ) Water Resour Manage G the heat conducted from the lake to the sediments (W m −2 ) β Bowen ratio (dimensionless) P the atmospheric pressure (kPa) c B the specific heat of air at constant pressure (0.61°C −1 ) T a the air temperature (°C) (°F for the Blaney-Criddle Jensen-Haise and Stephens-Stewart equations) T w the water surface temperature (°C) e s the saturation vapor pressure at the water surface temperature (Pa) e a the atmospheric vapor pressure (Pa) e a * the saturated vapor pressure at temperature of the air (mb) Δ the slope of the saturated vapor pressure-temperature curve (Pa°C −1 ) γ the psychometric coefficient (Pa°C −1 ) u the wind speed (m s −1 ) α Priestley-Taylor empirically derived constant (dimensionless) R s the incoming solar radiation (W m −2 ) C the mass-transfer coefficient (dimensionless) A s the area of the water body (hec) D the hours of daylight D TA the total annual hours of daylight SVD the saturated vapor density at mean air temperature (g m −3 ) e * a,max the saturated vapor pressures at maximum air temperature (Pa) e * a,min the saturated vapor pressures at minimum air temperature (Pa) E BREB the estimated evaporation values using BREB method (mm d −1 ) E eq the estimated evaporation values obtained by any methods (mm d −1 )

Balanço De Energia E Evaporação Da Água Com Baixa Turbidez Em Reservatórios De Uso Agrícola

“…Combinando as Eqs. 1, 2 e 3, a estimativa da evaporação da água do espelho d'água do reservatório R2 foi estimada como termo residual (Majidi et al, 2015) como se segue:…”

“…O volume de água evaporado de um lago ou reservatório depende de fatores relacionados à atmosfera (radiação solar, temperatura e umidade relativa do ar e velocidade do vento), à geometria e profundidade do reservatório, ao regime térmico e qualidade da água (turbidez) como também fatores associados ao ambiente circundante em termos de vegetação e topografia da área (Abtew, 2001;Gianniou & Antonopoulos, 2007;Nordbo et al, 2011;Rong et al, 2013;McJannet et al, 2013;Majidi et al, 2015). Gallego-Elvira et al (2010) estudaram a perda da água por evaporação em reservatórios revestidos no sudeste da Espanha para agricultura irrigada e, verificaram que em média 86,4% do saldo de radiação foi devido ao fluxo de calor latente (1310 mm ano -1 ).…”

Shoot water content and reference evapotranspiration for determination of crop evapotranspiration

“…6). This eases calculation of Kc without conducting complex soil water balance experiments, as these experiments usually require sensitive and sophisticated equipment Majidi et al, 2015;Ruiz-Peñalver et al, 2015) which are not readily available to resourcelimited farmers. In the current experiment, calculated K C increased with growth period and canopy expansion (Figs.…”

“…Moreover, the major strategy is sowing of drought tolerant and early maturing varieties of soybean (Mahasi et al, 2011). These varieties have different crop coefficients (Pereira et al, 2015), although, determination of crop coefficient for individual varieties is yet to be conducted, owing to the sensitivity, accuracy and, huge equipment investment required for such experiments Majidi et al, 2015;RuizPeñalver et al, 2015). Therefore, more efficient, effective, but also low-cost procedures for determining crop coefficient of these varieties is required.…”

Determinação Da Evaporação Pelo Método Do Balanço De Massa Em Reservatórios Artificiais Para Irrigação

“…O volume de água evaporado de um lago ou reservatório depende de fatores relacionados à atmosfera (radiação solar, temperatura e umidade relativa do ar e velocidade do vento), à geometria e profundidade do reservatório, ao regime térmico e qualidade da água (turbidez) bem como fatores associados ao ambiente circundante em termos de vegetação e topografia da área (Finch & Calver, 2008;Rodrigues, 2009;Curtarelli et al, 2013;Rong et al, 2013;McJannet et al, 2013;Majidi et al, 2015).…”